Bug 2230156 (CVE-2023-34319)

Summary:	CVE-2023-34319 xen: buffer overrun in netback due to unusual packet (XSA-432)
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, bhu, chwhite, crwood, dbohanno, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, ldoskova, lgoncalv, lleshchi, lzampier, nmurray, ptalbert, qzhao, rogbas, rrobaina, rvrbovsk, rysulliv, scweaver, tglozar, tyberry, vkumar, walters, wcosta, williams, wmealing, ycote, ymankad
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A buffer overrun vulnerability was found in the netback driver in Xen due to an unusual split packet. This flaw allows an unprivileged guest to cause a denial of service (DoS) of the host by sending network packets to the backend, causing the backend to crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-08-09 12:08:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2230157
Bug Blocks:	2230159

Description Pedro Sampaio 2023-08-08 19:24:09 UTC

The fix for XSA-423 added logic to Linux'es netback driver to deal with
a frontend splitting a packet in a way such that not all of the headers
would come in one piece.  Unfortunately the logic introduced there
didn't account for the extreme case of the entire packet being split
into as many pieces as permitted by the protocol, yet still being
smaller than the area that's specially dealt with to keep all (possible)
headers together.  Such an unusual packet would therefore trigger a
buffer overrun in the driver.

References:

https://xenbits.xen.org/xsa/advisory-432.html

Comment 1 Pedro Sampaio 2023-08-08 19:24:37 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2230157]

Comment 2 Mauro Matteo Cascella 2023-08-09 07:35:37 UTC

Upstream fix:
https://github.com/torvalds/linux/commit/534fc31d09b706a16d83533e16b5dc855caf7576

Comment 3 Product Security DevOps Team 2023-08-09 12:08:32 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2023-34319